1. The Atmosphere Chapter 15 section 1 Characteristics of the Atmosphere
S6E3b –Relate various atmosphere conditions to stages of the water cycle.

2. Does air have mass?
Explain your answer

3. The Atmosphere
The atmosphere is a mixture of gases that surrounds Earth and held in place by gravity.
Contains oxygen to breathe
Protects us from the suns’ damaging rays

4. Composition of the Atmosphere
Copy picture
1%:
Argon
Carbon dioxide
Neon
Helium
Methane
Krypton
Hydrogen

5. Bell Ringer: Feb. 10th
Compare cleavage and fracture.

6. Composition of the Atmosphere
Most common gas is nitrogen
Oxygen is 2nd most common
Small particles: dust, volcanic ash, sea salt, dirt, and smoke
Water – liquid water (water droplets)
solid water (snow and ice crystals),
water vapor (gas)
Stop: demonstration

7. Characteristics of the Atmosphere Atmospheric Pressure
Atmosphere is held around the Earth by gravity.
As gas molecules are pulled by gravity it causes air pressure.
Air pressure is the measure of the force with which air molecules push on a surface.
At sea level, there is 15 lbs of pressure per square inch.
Air pressure is the strongest at Earth’s surface because most gas molecules are pushing down on you.
As altitude increases, air pressure decreases.
As altitude decreases, density increases.

8. Stop and Think
When you let go of a helium balloon outside, why does it float away going further and further up?
Because helium is lighter than oxygen in the air (less dense)
Why does a hot air balloon float?
Because hot air rises (b/c it’s less dense)
Why can’t helicopters fly in the upper atmosphere?
There is not enough air molecules to help the helicopter move the propellers around in a circular motion. The higher the atmosphere, the less dense the air.

9. Changes in Temperature
As altitude increases there is a change in the temperature.
Temperature varies as a result from the way solar energy is absorbed by gases

10. Layers of the Atmosphere
Include information on your foldable.
Pages in textbook
Name of Layer
Altitude range
Temperature range
Other features